Studies will continue on the following general subjects: 1) Basal forebrain mechanisms in sleep. 2) Temporal organization of the states of sleep and wakefulness: a) Periodicity in sleep and waking performance in the cat; b) An ultradian sleep-wake cycle in the cat. 3) Neural substrates of sleep EEG patterns in sensorimotor cortex: a) Cortical- subcortical correlates of motor suppression during sleep and waking in the cat; b) Modulation of somatosensory evoked potentials in the cat as a function of concurrent EEG patterns in states of wakefulness and sleep. 4) Chronic single unit studies of the neural control of sleep: a) Discharge of units in brain stem sites; b) Discharge of units in the forebrain. 5) Brain stem reflex studies in relation to sleep and wakefulness.